Three-dimensional geophone

Abstract

A light weight and compact geophone assembly for detecting transient seismic signals along orthogonal axes. The geophone assembly having a plurality of geophones arranged within close proximity of each other within a compact housing. The geophones are interconnected to a conductor cable passing through the housing in a unique water-tight sealing arrangement. At the cable entrance into the housing, the conductor cable is surrounded by a tapered boot compressed about the cable by a sleeve which in turn is fixed in place by a locking nut. The locking nut is received by complementary threads at the cable entrance into the housing. When tightened, the locking nut forces the compression sleeve over the tapered surface of the boot, compressing the boot about the cable. In addition, the locking nut and compression sleeve urge the boot in compression between the cable and the housing. Located atop of the housing is a bubble leveling device. The level is recessed within the top of the housing and is equipped with a means for magnifying the bubble level. The bottom of the housing is equipped with ground coupling spikes to engage the housing with the earth. After the geophone assembly is firmly coupled to the earth, the operator adjusts the depth of each spike to level the housing. A level housing assures proper operation of the enclosed geophones within the housing.

I claim as my invention: 
     
       1. An apparatus for detecting transient signals along orthogonal axes, comprising in combination: (a) a housing;   (b) a plurality of sensors orthogonally disposed within said housing, at least one of the sensors being located above another of the sensors and separated therefrom by a compliant member;   (c) conductor means extending through said housing for interconnecting said sensors to a remote recording unit;   (d) means for substantially sealing said conductor means with said housing; and   (e) means disposed within the sealing means for anchoring the conductor means to the apparatus.   
     
     
       2. The apparatus of claim 1, wherein the conductor means extending through said housing for interconnecting said sensors to a remote recording unit is comprises of at least one cable having at least one conductor therein. 
     
     
       3. The apparatus as defined by claim 2, wherein the means for substantially sealing said conductor means with said housing, comprises: (a) a boot enclosing a portion of the cable proximate the housing;   (b) a compression ring concentrically received about the boot; and   (c) a locking nut concentrically received about the compression ring, the locking nut threadably received by the housing, forcing the compression ring up and over the boot thereby compressing the boot tightly about the cable and urging the boot in a sealing engagement with the housing.   
     
     
       4. The apparatus as defined in claim 1, further comprising means for determining when said housing is level. 
     
     
       5. An assembly for detecting orthogonal components of a transient signal propagating through a medium, comprising in combination: (a) a housing coupled to the medium;   (b) a plurality of sensors fixed within the housing and disposed along orthogonal axes, at least one of the sensors being disposed above another of the sensors and separated therefrom by a compliant member;   (c) conductor means extending through the housing for interconnecting the sensors to a remote recording device;   (d) means concentrically about the conductor means for sealing the conductor means with the housing;   (e) means within the housing for determining when the housing is in a preferred orientation with respect to a gravitational vertical; and   (f) means, integral within the sealing means for fixing the conductor means with the assembly.   
     
     
       6. The assembly as defined in claim 5, wherein the means concentrically about the conductor means for sealing the conductor means with the housing, comprises: (a) a elastomeric boot;   (b) means engaging the housing and concentrically received about the boot for urging the boot in compression with both the housing and the conductor means.   
     
     
       7. The apparatus as defined in claim 5, wherein the conductor means, comprises a conductor cable having at least a single conductor therein. 
     
     
       8. The apparatus as defined in claim 5, wherein at least one of the sensors is disposed above another of the sensors. 
     
     
       9. A three-dimensional geophone assembly for detecting orthogonal components of a transient seismic signal propagating through the earth, comprising in combination: (a) a housing defining a cavity therein and having at least one opening extending through a side thereof;   (b) a plurality of sensors orthogonally disposed within the cavity, at least one of the sensors disposed above the plurality and separated therefrom by a compliant member;   (c) transmission means extending through the opening in the housing for interconnecting the plurality of sensors to a remote unit;   (d) a compliant boot having a tapered exterior surface engaging the opening and the transmission means;   (e) a compression sleeve concentrically received about and adapted to engage the tapered surface of the compliant boot for placing the boot in sealing engagement about the transmission means;   (f) a locking nut engaging the compression means the housing for retaining the boot in sealing engagement with the housing and about the transmission means;   (g) means coupled to the housing for indicating a predetermined orientation of the housing with respect to a gravitational vertical; and   (h) means coupled to the housing for penetrating the earth and coupling the housing thereto.   
     
     
       10. The geophone assembly as defined in claim 9, wherein the retaining means comprises a locking nut received by the housing. 
     
     
       11. The geophone assembly as defined in claim 9, further comprising means for anchoring the transmission means with the geophone assembly.